/*
 * [New BSD License]
 * Copyright (c) 2011-2012, Brackit Project Team <info@brackit.org>  
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Brackit Project Team nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.brackit.xquery.operator;

import java.io.PrintStream;
import java.util.Arrays;

import org.brackit.xquery.QueryContext;
import org.brackit.xquery.QueryException;
import org.brackit.xquery.Tuple;
import org.brackit.xquery.xdm.Sequence;

/**
 * 
 * @author Sebastian Baechle
 * 
 */
public class Print implements Operator {
	private final Operator in;
	private final PrintStream out;

	public Print(Operator in, PrintStream out) {
		this.in = in;
		this.out = out;
	}

	protected class PrintCursor implements Cursor {
		private final Cursor c;
		private final Tuple[] t;
		private final PrintStream out;

		private int maxSize = 20;

		private int count;

		public PrintCursor(Cursor c, Tuple[] t, PrintStream out) {
			this.c = c;
			this.t = t;
			this.out = out;
		}

		@Override
		public void close(QueryContext ctx) {
			c.close(ctx);
			out.println("---");
			out.print(count);
			out.println(" results");
			out.flush();
		}

		@Override
		public Tuple next(QueryContext ctx) throws QueryException {
			Tuple next = c.next(ctx);
			if (next != null) {
				count++;
				int size = next.getSize();
				out.print("|");
				for (int i = 0; i < size; i++) {
					out.print(' ');
					Sequence sequence = next.get(i);
					String s = (sequence != null) ? asString(ctx, sequence)
							: "()";
					s = shrinkOrPad(s);
					out.print(s);
					out.print(" |");
				}
				out.print('\n');
			}
			return next;
		}

		private String shrinkOrPad(String s) {
			int length = s.length();

			if (length == maxSize) {
				return s;
			}
			if (length > maxSize) {
				return s.substring(0, maxSize);
			}

			int toAdd = (maxSize - length);
			char[] result = new char[maxSize];

			int i = 0;
			while (i < (toAdd / 2)) {
				result[i++] = ' ';
			}
			System.arraycopy(s.toCharArray(), 0, result, i, length);
			int j = i + length;
			while (i++ < toAdd) {
				result[j++] = ' ';
			}
			return new String(result);

		}

		@Override
		public void open(QueryContext ctx) throws QueryException {
			c.open(ctx);
			count = 0;
			out.print("--- ");
			out.println(Arrays.toString(t));
		}
	}

	@Override
	public Cursor create(QueryContext ctx, Tuple tuple) throws QueryException {
		return new PrintCursor(in.create(ctx, tuple), new Tuple[] { tuple },
				out);
	}

	@Override
	public Cursor create(QueryContext ctx, Tuple[] buf, int len)
			throws QueryException {
		return new PrintCursor(in.create(ctx, buf, len), buf, out);
	}

	@Override
	public int tupleWidth(int initSize) {
		return in.tupleWidth(initSize);
	}

	public String asString(QueryContext ctx, Sequence sequence)
			throws QueryException {
		return sequence.toString();
	}
}
